From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Comparing the performance and engine characteristics of the Bentley III against other models.
| Identifier | ExFiles\Box 97\1\ scan0236 | |
| Date | 25th October 1938 | |
| SECRET. Sg.{Arthur F. Sidgreaves - MD} from Rm.{William Robotham - Chief Engineer} c. Hs.{Lord Ernest Hives - Chair} c. By.{R.W. Bailey - Chief Engineer} c. C. c. Cx.{Major Len W. Cox - Advertising Manager} c. Hly. re: BENTLEY III. / 400 . With reference to Cx{Major Len W. Cox - Advertising Manager}1/KH10.10.38., dealing in order with the points raised:- Performance. We find that the best way of estimating accurately the relative performance of two cars is to run them side by side. We presume that in this particular trial this was not done, because, if so, it would have been apparent that there is little or no difference in performance between B.B.V. and the present 'M' Series Bentley. Our experimental 'M' Series lapped a 89 m.p.h., and on the same day B.B.V. lapped at exactly the same speed. We timed the Bentley III to do 97 1/2 m.p.h. on the Autobahn under extremely favourable conditions. Briefly, the production B.III may be expected to have the same performance as an 'M' Series Bentley, provided it is fitted with a body of the same weight and of the same air resistance. With reference to the remark about the difficulty of obtaining 4,500 revs., with the introduction of 'M' Series we took the opportunity of causing the engine power to fall off rapidly above 4,200 revs. as with the introduction of the overdrive it is no longer necessary to run the engine above this speed in order to obtain maximum m.p.h., this will prevent customers doing damage when running in direct. Engine Roughness and Noise. Here we suggest that your impression was derived from the fact that you have recently been driving a Wraith. There is no doubt at all that the engine is both smoother and more silent than the 'M' Series cars under the same conditions. Furthermore, the final B.III will be a considerably smoother and more silent car than S.B.V. | ||